The present invention relates generally to transmission of electrical signals within electronic packages, and more particularly to the transmission of electrical signals to or from dies for integrated circuits.
Integrated circuits are often formed on one or more dies placed within a package. Within the package signals are provided to the die, or chip. Often the signals are provided using wires wire bonded to the die.
Integrated circuits, however, are increasingly being operated at very high clock rates using very high frequency signals, and doing so with technology process that form very dense circuitry. The high frequency signals pose difficulties when used with wire bonds as the wires are often not shielded, allowing for increased signal attenuation, crosstalk, and irradiation, as well as heat dissipation and other problems. Moreover, wire bonds generally become very inductive at high frequencies, and it is often difficult to properly match impedances.
Flip chip mounting schemes are sometimes used to increase signal transfer performance. The flip chip configuration, however, is more expensive. In addition, thermal dissipation characteristics may not be sufficient for high frequency circuits, particularly high frequency circuits using technology which is less electrically efficient.